To create FrameMaker book

I require to create a FrameMaker book by adding 3000 files to it. What are the different properties to be set to create a book when it contains a large number of files ?

I am currently using the F_ApiNewSeriesObject(bookId, FO_BookComponent, 0) and F_ApiSetString to add the component files to the book. However  after adding 300 files, the process begins to get slower.

Thanks,

Asha Rayakar